Over the past five years a craze for riding bicycles with only one gear and no freewheel has taken off, in New York, London, Sydney and cities all around the world. We take a long hard look at the merits and excesses of the scene. Featuring the author of the Bike Snob NYC blog, Roxy Erickson of London's 'Trixie Chix' and Gabriel Norgueira who is one of the prime movers in the small but growing fixed wheel crowd in Curitiba, Brazil.